books.google.co.uk - This book is one of the most reliable sources on the beginnings of the Islamic Empire. It begins with the wars of the Prophet Muhammad, followed by accounts of the ridda, the conquests of Syria, Armenia, Egypt, and the Maghrib, and lastly, the occupation of Iraq and Persia....http://books.google.co.uk/books/about/The_Origins_of_the_Islamic_State.html?id=DrtLsKXt1osC&utm_source=gb-gplus-shareThe Origins of the Islamic State